• The NTN series feature thermo-ventilating units equipped with a ventilator featuring a belt-driven engine. The structure consists of a girder-built underframe made of anticorodal extruded aluminium section bars that are linked by means of Nylon joints. The cabinet consists of multi-layer, painted steel panels. The engine-ventilator group is isolated from the rest of the structure by means of suitable buffers on the basement and a Neoprene anti-vibrating joint between the air inlet and the panels. The dual-intake centrifugal fans featuring forward-oriented fins are balanced both statically and dynamically. The 95, 130 and 175 versions are equipped with twin ventilators. The engine-ventilator group features variable pitch pulleys and V-belts for all versions. The 4-pole electric engines are ventilated outside and isolated according to F-class standards, with IP55 protection mounted on dedicated guides allowing to regulate belt tension. The place to install batteries can host both heating and/or cooling batteries and has been designed to be equipped with two batteries – oriented either horizontally or vertically. All batteries feature copper piping and aluminium fins: devices working with hot water have 2 or 4 ranks, while devices working with chilled water have 4 or 6 ranks. The filtering section is equipped with multiply synthetic cell filters with 85% ponderal filtering efficiency. The NTN units are also available with centrifugal fan whose engine is directly coupled to the fan wheel (NTN/D version).